I am a two-digit perfect square. The sum of my digits is also a perfect square, and my ones digit is twice my tens digit. What number am I?
36
36 is a perfect square (6^2). Its digits sum to 3 + 6 = 9 (which is 3^2), and its ones digit (6) is twice its tens digit (3).
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Easy. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
More math riddles
I am a two-digit prime number less than 30. Dividing me by 4 leaves a remainder of 3. Adding 2 to me turns me into a multiple of 5. What number am I?
Roses cost 2 dollars each. How much do 7 roses cost?
One corn cob costs 4 dollars. How many dollars do 8 corn cobs cost?
Half of the 20 sand castles on the table are taken away. How many sand castles are left on the table?
Eli has 8 shells. Lily has twice as many. How many shells do they have together?
Ava makes 4 rows of 3 sand castles and adds 2 more at the end. How many sand castles are there in all?